This invention relates to aliphatic dibasic acids and aliphatic glycols. More particularly, this invention relates to low molecular weight vinyl polymers with chain terminating reactive carboxyl or hydroxyl groups, methods for their preparation, and high polymers that can be made therefrom.
Aliphatic dibasic acids and aliphatic glycols are extremely important groups of industrial chemicals. They are used for many purposes, such as plasticizers and lubricants, and of even greater importance is their use as monomers in the preparation of high polymers. With respect to their use as monomers in polymerization processes, these materials are extremely versatile and may be used in the formation of a large number of condensation polymers. By way of example of some of the more commercially significant condensation polymers that may be so formed are the polyesters which can readily be prepared from the reaction between the dibasic acids and glycols themselves; polyamides which can be prepared through the reaction of a dibasic acid with a diamine; polyurethanes and polyureas which can be prepared by the reaction of a dihydric alcohol with diisocyanates; and polyepoxies that can be prepared by the reaction of an epoxy either with a dibasic acid or a dihydric alcohol.
It is, of course, apparent that, as these difunctional monomers become an internal part of the polymeric chain, various physical and chemical properties of the high polymer will be innfluenced by the structure of the difunctional monomer. For example, the structure of the difunctional monomeric compounds may have significant effects in determining the extent and nature of the crystalline and amorphous regions within the polymer. This, in turn, can significantly affect physical and rheological properties of the polymer such as strength, impact, moisture absorption, elongation, elasticity, cold flow, heat distortion temperature, low temperature embrittlement, dielectric properties, etc., etc.
While a number of difunctional compounds of the subject type are theoretically available for use as monomers, in point of fact, only comparatively few find significant commercial utilization in the preparation of high polymers, variously because the vast majority of these difunctional compounds may not be readily available, they may be hard to synthesize, or they may be comparatively expensive as compared with other difunctional materials that are capable of producing equivalent or better combinations of properties.